Cognitive impairment associated with diseases of aging is a major public health problem. Neuropsychological tests of cognitive abilities have long been used to measure changes in cognition related to diseases like Alzheimer's disease. The use of cognitive tests is complicated by influences on test performance of variables that are not related to disease and can result in measurement bias in ethnically and demographically diverse populations. The challenge is to measure disease effects in a way that is unbiased by extraneous influences associated with ethnicity and demographic heterogeneity. This is a competing renewal application for a project initiated in 1992 that has an overarching goal of developing and validating psychometrically sophisticated neuropsychological tests that can be used effectively in English and Spanish speaking older individuals. The Spanish and English Neuropsychological Assessment Scales (SENAS) have been developed in this project to meet these goals using advanced psychometric methods. The goals for the next cycle will be to: 1) independently model disease effects and effects of ethnicity and associated variables on cognition using cross-sectional and longitudinal data, 2) further validate the SENAS as a measure of cognitive impairment and decline that can be used effectively with English and Spanish speakers from different ethnic backgrounds, and 3) develop an item bank for SENAS scales that can be incorporated into a computerized adaptive testing format using emerging technology. The following specific aims will be addressed: 1) Characterize the item-level and scale- level effects of ethnicity and associated variables and proxies for disease status on SENAS measures, 2) Evaluate the relative sensitivity of SENAS measures to change in global and regional structural MRI variables in different language and ethnic groups, 3) Develop a model to explain the contributions of disease effects and ethnicity and related variables to baseline cognition and longitudinal change in cognition, and 4) Develop and validate computerized adaptive testing (CAT) methods for SENAS scales that will maximize efficiency and minimize burden associated with cognitive testing, and promote standardization and availability of SENAS methods.

Public Health Relevance

This project will examine multiple influences on cognitive function in ethnically and demographically diverse older people demographically. It will provide information that will increase understanding of cognitive decline in older people and will improve our ability to measure these changes.